There are many applications, ranging from consumer electronics to telecommunications and the like, in which electrically-driven devices (e.g., semiconductor-based electronic devices) capable of performing various tasks are packed in close proximity in a small form factor to serve various needs. Such electrically-driven devices may include, for example, driver circuits, logic processors, graphics processors, memory chips, laser diodes including edge-emitting lasers and vertical-cavity surface-emitting lasers (VCSELs), light-emitting diodes (LEDs), photodiodes, sensors, etc. Many of such electrically-driven devices inevitably generate thermal energy, or heat, in operation and thus are heat sources during operation as well as for a period of time after power off. As the number and complexity of the functionalities performed by such electrically-driven devices continue to increase and as the distance between electrically-driven devices in the small form factor continues to decrease, heat generated by such electrically-driven devices, as heat sources, present technical challenges that need to be addressed.
For one thing, performance, useful lifespan, or both, of an electrically-driven device may be significantly impacted if the heat generated by the device is not adequately dissipated or otherwise removed from the device. Moreover, given the close proximity between two or more electrically-driven devices on the same substrate, e.g., printed circuit board (PCB), in some applications, a phenomenon of thermal coupling between the two or more devices in close proximity may occur and result in the heat generated by one of the devices being transferred to one or more adjacent devices. When thermal coupling occurs, at least a portion of the heat generated by a first electrically-driven devices is transferred to a second electrically-driven device in close proximity due to temperature gradient, such that the temperature of the second electrically-driven device rises to a point higher than it would be when no heat is transferred from the first electrically-driven device to the second electrically-driven device. More specifically, when thermal coupling occurs and when no adequate heat transfer mechanism exists, heat generated by electrically-driven devices in close proximity may detrimentally deteriorate the performance and useful lifespan of some or all of the affected devices. As electrically-driven devices generate heat, they are referred to as heat-generating devices hereinafter.